Magnet drive for take up spool spindle in circular knitting machines

ABSTRACT

Magnetic drives for turning the spindle of a take-up spool in circular knitting machines; the wheel on the spindle orbits past the magnet(s) or the magnet(s) orbit past wheel; and means for adjusting the distance between the wheel and magnet(s) in response to increasing diameter of the knitted fabric wound on the spool or in response to program control.

United States Patent I Illillll Schaack 1 51 Oct. 3, 1972' MAGNET DRIVE FOR TAKE UP SPOOL 2,179,334 1 H1939 Keyes ..57/ 18 SPINDLE IN CIRCULAR KNITTING 1,862,267 6/1932 l-lonig ..310/103 MACHINES 2,365,691 12/ l 944 Fodor ..242/75 .51 2,610,806 '9 I952 Lath ..242 45 [72] Inventor: Kurt Schaack, Lenneper Str. 40, I mp I Wuppertal, Germany FOREIGN PATENTS OR APPLICATIONS [22] Filed: June 22, 1970 1,176,203 4/1959 France I I [2]] App. No; 48,380 858,063 -l/ 1961 Great Bntarn Primary Examiner-Wm. Carter Reynolds [30] Foreign Application Pri rity Data Attomey-Johnston, Root, OKeefi'e, Keil, Thompson June 28, 1969 Germany ..P 19 32 944.3 i

[57] ABSTRAT 521 US. Cl ..66/151 51 1m. (:1. ..D04b 15/88 Magnet dr'ves mmmg sPmdle Of a -"P [58] Field of Search ..66/151 152 153- 242/755 SP001 circular knitting machines; the Wheel spindle orbits past the magnet(s) or the magnet(s) [56] References Cited orbit past wheel; and means for adjusting the distance between the wheel and magnet(s) in response to increasing diameter of the knitted fabric wound on the spool 01' in response to program control.

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sum 2 or 2 HHI I INVENTOR Q KURT SCHAACK- ATT'YS MAGNET DRIVE FOR TAKE UP SPOOL SPINDLE IN CIRCULAR'KNITTING MACHINES lNTRODUCT ION This invention relates to a winding mechanism for winding knitting in circular knitting machines. The spindle for the spool and its rotary journal in the knitted fabric winding mechanism is fixedly connected to a needle cylinder coacting with a cam cylinder by which the needles are actuated.

Various forms of winding mechanisms for circular knitting machines are already known, all of which have more or less serious disadvantages. Some known mechanisms comprise a pawl which rotates the ratchet wheel for the winding spools spindle as it moves past the pawl. In this arrangement, the knitting is automatically moved forward at intervals determined by the toothing of the ratchet wheel. it is not possible with a mechanism of this kind to obtain a uniform stitch strength.

Other known mechanisms provide the winding spools spindle with its own drive or connect the drive of the needle cylinder with the spindle through a gear system. In this case, the spindle and the drive are coupled through slip clutches, automatically engageable and disengageable dog clutches or belt drives with variable belt tension. Mechanisms are also known in which the winding spools spindle is rotated by additional friction rollers, the friction roller itself being driven imprecisely in the same way as described above.

These known mechanisms operate either with inadequate reliability or with inadequate uniformity or are extremely complicated and expensive. in some cases, they are also subjected to considerable wear and tear.

THE INVENTION An object of the invention is to provide improvements capable of providing knitted hosiery with uniform, adjustable stitch strength in circular knitting machines. Y More specifically, the problem which. the invention seeks to solve is to provide a winding mechanism for circular knitting machines by means of which it is possible to obtain a uniform adjustable level of tension in the knitted hosiery through a positive connection between the winding spool s spindle and the rotatable needle.

According to the invention there is provided a winding mechanism for a circular knitting machine having a spool mounted on a shaft or spindle and positively connected with a rotatable needle cylinder of the knitting machine. The spools spindle hub is fixedly connected with the needle cylinder. The mechanism comprises a wheel mounted on the spindle or shaft, and at least one magnet cooperating with this this wheel. The magnet is mounted on a ring at a distance from the wheel sufficiently wide to form an air gap. The wheel is made of a ferromagnetic material and/or of an electrically highly conductive material at least on these surfaces opposite the magnet or magnets. The magnet or magnets lie in a plane perpendicular of the axis of rotation of the needle cylinder.

in one particular embodiment of the invention, the wheel is provided with a brake acting, preferably positively, only against the unwinding direction of rotation of the winding spindle and its spool. The object of this brake is to prevent unwinding of the spooled, knitted hosiery and its consequent reduction in the tension applied to the knitted hosiery when the wheel moves over a surface on which there is no magnet. in cases where several magnets are used, they are preferably arranged in a circle whose radius corresponds to the distance of the wheel from the axis of the cam cylinder.

In another preferred embodiment, the size of the air gap between the wheel and the magnet or magnets is variable to allow the tension applied to the knitted hosiery to be readily adjusted.

In one preferred embodiment of the invention, the magnet poles lie parallel to the axis of rotation of the spindle and wheel. However, the poles of the magnets alternatively can be situated radially of the aforesaid axis. Here the wheel preferably is provided with a groove in its surface.

In another embodiment, one or more horseshoe magnets are used, and the wheel is preferably in the form of a circular disc which is orbited between the poles of one or more horseshoe magnets. The disc is mounted coaxially with the spool.

In order to maintain the tension applied to the knitted hosiery at a constant level, a device can be provided for probing the package diameter on the winding spool. The device influences the size of the air gap and/or the intensity of the magnetic field. In another embodiment of the invention, required changes in the tension applied to the knitted hosiery can be effected during production by providing a program-controlled regulating unit which influences the size of the air gap and/or the intensity of the magnetic field.

In operation the wheel mounted coaxially on the spool and its spindle in the winding mechanism makes an orbiting movement relative to the magnet or magnets arranged on a ring. There is an air gap between the magnet or magnets and the wheel. The wheel consists of a ferromagnetic material and/or an electrically highly conductive material at least on those surfaces opposite the magnets. When making the relative movement, the wheel is braked by the magnetic field as it passes over the magnets, producing on the wheel a torque which rotates the wheel and the take-off spool and its spindle until a suitable tension is applied to the knitted hosiery. The take-off spindle contains a suitable brake or arresting device which allows rotation in one direction only the winding direction.

The degree of tension applied to the knitted hosiery is primarily governed, all other things being equal, by the intensity of the effective magnetic field and by the extent of the relative movement between the wheel and the magnet or magnets. The material on those surfaces of the wheel opposite the magnet or magnets is also of importance. The intensity of the effective magnetic field is governed by the width of the air gap between the magnet and the wheel and can be made variable by varying the width of the air gap. In cases where electromagnets are used, it is possible to adjust the intensity of the effective magnetic field by regulating the electrical current flowing in the magnetic coil.

If it is intended to produce knitted goods with very narrow stitches, it is sufficient to apply a single magnet. In cases where wider stitches are required, it is best to use several magnets arranged at equal intervals apart around the periphery of the annular magnet support, or

even a ring magnet. In this case, the poles of the magnets. should be arranged in the same direction and parallel to one another. If the poles lie radially .of the axis of rotation of the wheel, the wheel is best provided on its magnet-opposing surface with a groove through which the magnets may pass or be passed by the wheel. In cases where horseshoe magnets are used, a circular disc fixed coaxially to the spindle is used as the wheel, the edge of the disc passing between the poles of the magnets. 'In principle, any type of magnet may be used providing it is of adequate field intensity.

As a fabric continues to be wound on to the roller, the force acting on it at the take-up point changes despite the uniform force acting on the wheel. However, in order to obtain a consistently uniform degree of tension, the intensity of the effective magnetic field is regulated in dependence upon the diameter of wound fabric package in such a way that the peripheral force remains uniform at the point where the hosiery runs on to the package. This can be done for example by probing the package diameter and allowing the probe value thus obtained to act on the effective magnetic field. In

addition, the effective magnetic field can be controlled for example through a cam disc or a magnetic tape containing the requisite control quantities as program. In this case, however, any required changes in the tension applied to the knitted hosiery can also be effected, optionally during production.

The present invention can be applied to circular knitting machines with a stationary or a rotating needle cylinder. In the first case, the ring provided with the magnets rotates together with the cam cylinder actuating the needles about its axis and the spools spindle together with its wheel remains in the rest position about this axis. In the second case, the needle cylinder and the spindle together with its wheel rotate about the axis of the needle cylinder while the ring with the magnet(s) and the cam cylinder remain in the rest position about this axis.

THE DRAWINGS which a horseshoe magnet is used for the winding mechanism according to the invention;

FIG. 4 is a side elevation of a wheel with a peripheral groove and a coacting magnet; and

FIG. 5 is a top plan view of a magnet support ring with four magnets mounted thereon.

In the embodiment of FIG. 1, the machine frame has a fixed mounting ring 11 thereon. The ring 11 and its cap ring 13 supports a journal bearing 12 for the rotatable tube 14. The tube 14 extends through the sleeve 15 and is connected at its upper end to the rotating needle cylinder (not shown). The tube 14 rotates about the axis A.

The needle cylinder (not shown) revolves about axis A to cause its needles to be actuated by the stationary cam cylinder (not shown). An arm 21 rigidly connects the hub 22 of the spindle 23 to the flange 20 of the tube 14. The hub has an axial bore 24 which receives roller bearings 25 and 26, which are held in spaced relationship by the cap 27 and spacer rings 27a and 27b. The roller bearings rotatably support the smaller diameter end 28 of the spindle 23. The remainder of the spindle comprises the larger diameter medial segment 29, a

tapered segment 30, a smaller diameter segment 31,

and a removable cap 32. The hub 22 with its roller bearings 25 and 26 serve as the journal for the spindle 23.

A knitted fabric take-up, spool 35 is mounted removably on the spindle 23 and is held firmly thereon by the spring-loaded head 36. The diameter of fabric winding 38 is felt by the roller 39 rotatably mounted on a yoke 40 of the vertical arm 41. The arm is supported on lever 42 fulcrumed on the bracket 43 which is fixedly mounted on the underside of the stationary magnet support ring 44. The arm 41 passes through a central hole 45 in the ring 44.

The single magnet 47 is a permanent bar magnet or a disc-shaped permanent wafer 47 supported on magnet support 46, which in turn slides in hub 48 and rests on the mushroom head 49 on the opposite end of lever 42.

The spindle 23 has mounted fixedly and coaxially thereon a wheel 50 which orbits over magnet 47 as the needle cylinder 20 and spindle 23 rotate about axis A. The wheel 50 is composed of a hub 51 tightly seated on the spindle, a ring face 52 and a flange 53.

A stationary brake 55 extends into the annular space 54. Its flange 59 is mounted fixedly on hub 22. The

brake is a one direction of rotation brake and is illustrated in FIG. 2. It has a ring 56 having in its periphery axial grooves 57 which are circularly-arced at one end and slope at the other end. Rollers 58 rotate in the grooves. The wheel 50 may rotate freely in the direction of the arrow while rollers 58 are urged against the circularly arced ends of grooves 57. It is braked positively against opposite rotation by a wedging action as rollers 58 are urged up the sloping ends of grooves The embodiment of FIG. 4 uses agrooved wheel 50a which orbits past the permanent bar 47b the air gap being in the peripheral groove 62 in the wheel. FIG; 5 shows a magnet mounting ring 44 with a plurality of magnets 47 in this case, four magnets at equal radii and at equi-angular spacing in a circle having a radius substantially equal to the distance of the wheel from axis A.

In the arrangement shown in FIG. 3, a horseshoe magnet 47a is used as the magnet. In this case, a ring 61 is provided on the wheel 50 in such a way that the disc passes between the poles of the horseshoe magnet at a distance forming an air gap and can impart the necessary forward movement to the winding spindle as the ring orbits through the magnet.

The wheels 50 or 500 and the ring 61 (FIG. 3) are made of a ferromagnetic material or an electrically highly conductive material at least on those surfaces opposite the magnets 47, 47a or 47b. As the wheel 50 or 500 or the ring 61 .orbits over or through the respective. magnet, the magnetic attraction between the wheel or ring within the magnetic field of the respective magnet imparts a rotating action to the wheel or ring. This rotating action is in the winding direction of the winding on the spool 35. Thus, the wheel 50 or 500 turns the spindle 23 and take up spool 35 by an amount sufficient to maintain the tension in the knitted fabric 37 each time the wheel 50 or 50a passes over or through a magnet.

The wheel can only rotate freely in the winding direction. If the tension applied to the knitted hosiery is to remain constant, the width of the air gap between the wheel and magnet is varied for example by means of the lever arrangement in response to the thickness of the package. The package diameter is measured by a feeler roller, as a result of which the change of tension in the knitted hosiery accompanying the increase in the diameter of the package is compensated for. The lever arrangement shown in only a diagrammatic illustration and would have to be amplified by appropriate transmission members, which have been omitted for the sake of clarity, because the air gap only has to be changed by a few millimeters when the package diameter changes by a few decimeters.

The one-way brake through which the wheel can only rotate freely in the winding direction is a kind of freewheel in which, in the event of rotation opposite the winding direction, the wheel is arrested .or braked by the rollers being pressed into V-gaps between the grooves and the inside of the wheel. In the event of rotation in the winding direction, the wheel moves freely over the rollers.

. It is thought that the invention and its numerous attendant advantages will be fully understood from the foregoing description, and its is obvious that numerous v changes may be made in the form, construction and arrangement of the several parts without departing from the'spirit or scope of the invention, or sacrificing any of its attendant advantages, the forms herein disclosed being preferred embodiments for the purpose of illustrating the invention.

The invention is hereby claimed as follows:

1. A winding device for a circular knitting machine having a cam cylinder actuating the needles of a rotatable needle cylinder rotatable about a vertical axis, which comprises a horizontal spindle with a take up spool mounted thereon, a vertical tube rotatable with said needle cylinder, a journal of said spindle being rigidly connected with said tube, a coaxial wheel on said spindle and orbitable about said vertical axis as said spindle rotates about said vertical axis, and at least one magnet positioned in the orbital path of said wheel and mounted at a distance from he wheel sufficiently wide to form an air gap when the wheel passes across the magnet, the wheel consisting of a ferromagnetic material or an electrically highly conductive material at least on those surfaces opposite the magnet and the wheel being rotated by the magnetic field of said magnet as it passes across the magnet to thereby rotate said spindle and the take-up spool thereon about the axis of said spindle.

2. A mechanism as claimed in claim 1, said wheel having a one-way brake acting against the direction of unwinding a knitted fabric off the winding spool.

3. A mechanism as claimed in claim 2, and means to provide positive braking action of said brake.

4. A mechanism as claimed in claim 1, wherein several of said magnets are arranged in a circle whose radius corresponds to the distance of its wheel from the axis of orbit.

5. A mechanism as claimed in claim 1, and means to vary the size of the air gap between the wheel and the magnet.

6. A mechanism as claimed in claim 1, wherein the poles of the magnet lie parallel to the axis of orbit of the wheel.

7. A mechanism as claimed in claim 1, wherein the magnet poles of said magnet are situated radially of the axis of orbit of the wheel.

8. A mechanismas claimed in claim 1, wherein the wheel has peripheral groove into which the magnet projects.

9. A mechanism as claimed in claim 1, wherein the magnet is a horseshoe magnet and the wheel includes a circular ring which passes between the poles of the horseshoe magnet, the ring being coaxial with the spindle.

10. A mechanism as claimed in claim 1, and means to probe the diameter of the package on the winding spool and to effect the magnetic field strength applied to said wheel. I 

1. A winding device for a circular knitting machine having a cam cylinder actuating the needles of a rotatable needle cylinder rotatable about a vertical axis, which comprises a horizontal spindle with a take up spool mounted thereon, a vertical tube rotatable with said needle cylinder, a journal of said spindle being rigidly connected with said tube, a coaxial wheel on said spindle and orbitable about said vertical axis as said spindle rotates about said vertical axis, and at least one magnet positioned in the orbital path of said wheel and mounted at a distance from he wheel sufficiently wide to form an air gap when the wheel passes across the magnet, the wheel consisting of a ferromagnetic material or an electrically highly conductive material at least on those surfaces opposite the magnet and the wheel being rotated by the magnetic field of said magnet as it passes across the magnet to thereby rotate said spindle and the take-up spool thereon about the axis of said spindle.
 2. A mechanism as claimed in claim 1, said wheel having a one-way brake acting against the direction of unwinding a knitted fabric off the winding spool.
 3. A mechanism as claimed in claim 2, and means to provide positive braking action of said brake.
 4. A mechanism as claimed in claim 1, wherein several of said magnets are arranged in a circle whose radius corresponds to the distance of its wheel from the axis of orbit.
 5. A mechanism as claimed in claim 1, and means to vary the size of the air gap between the wheel and the magnet.
 6. A mechanism as claimed in claim 1, wherein the poles of the magnet lie parallel to the axis of orbit of the wheel.
 7. A mechanism as claimed in claim 1, wherein the magnet poles of said magnet are situated radially of the axis of orbit of the wheel.
 8. A mechanism as claimed in claim 1, wherein the wheel has peripheral groove into which the magnet projects.
 9. A mechanism as claimed in claim 1, wherein the magnet is a horseshoe magnet and the wheel includes a circular ring which passes between the poles of the horseshoe magnet, the ring being coaxial with the spindle.
 10. A mechanism as claimed in claim 1, and means to probe the diameter of the package on the winding spool and to effect the magnetic field strength applied to said wheel. 